Energetic Beauty; Water Hyacinth

Water hyacinth photo by Terry W. Burger

If  you have a decorative pond as part of your gardening addiction, plants should be a major part of that equation.

One of the easiest things to grow for your pond is water hyacinth.

Beware, though, the Central and South American native species, for all its lustrous green leaves and lilac-toned flowers, the hyacinth can be almost as energetic and the giant alien plant in the film “Little Shop of Horrors.”

Available anywhere plants for water gardens are sold, the floating hyacinth, Eichornia crassipes, have wandered far from its native lands, and are now found around the world in the tropics and subtropics. According to several sources, it is thought to have found its way to New Orleans’ Cotton States Exposition in 1884. It is now found in 53 countries, and has colonized itself in 13 states in the U.S.
In those areas of the U.S. that fit that climatic description, the hyacinth is a royal pain.

Fishing boats mired in a tangle of water hyacinth along the shores of Lake Victoria.

They clog waterways and generally make a nuisance of themselves, for some of the same reasons they can be a gorgeous disaster in your backyard pond.
Get this: The hyacinth is the fastest, or at least one of the fastest, growing plant on record. At least one study showed that two plants, presumably in an ideal growing environment, produced 1,200 daughter plants in four months. And that’s just spreading by rhizomes. Not satisfied with that, a single hyacinth can produce as many as 5,000 seeds. The plant can double its population is as little as six days.

The plants grow so thick that during World War II in Ceylon, now Sri Lanka, hyacinths were grown on large marshy areas to fool Japanese pilots into thinking what they were seeing were open fields. They would land on what they thought was hard ground, and that would be the end of them.

If allowed to grow into a dense mat, the hyacinth restricts light underneath them and depletes oxygen levels.

Water hyacinth in Terry's pond. Photo by Terry W. Burger

You see where this is going?

This past June we toddled down to our friendly vendor, Gettysburg Water Gardens, and bought two plants, plopping them down in the higher of our two ponds. The water runs out of that pond, along a “creek,” and over a falls into the lower pond, where it gets sucked through a skimmer and pumped back up to start all over.

We hoped our new plants would thrive.  Boy did they ever.

Fast forward to mid-August. The entire upper pond is covered with a solid mass of water hyacinths. More, they have spread over the upper spillway and have lunged nearly halfway down the run to the lower pond. The glossy green leaves towered nearly three feet in some places, their purple blooms showy enough to stop traffic on our street.

But there was a problem. The ponds were losing water. Leaks appeared in several areas around the perimeter of the upper pond, the newer of the two. We dug, we bolstered the stones beneath the pond liner edges. For every leak we fixed, another would appear.
We began to have dark thoughts about the fellow who installed the new pond.

And then, in a moment of inspiration, Sue went to the upper pond and started ripping up hyacinth plants at the spillway. Immediately, the amount of water running down the chute and over the falls increased enormously.

Terry and Sue's pond. Photo by Terry W. Burger

The hyacinths had dammed up our pond.

The culprit was their root system, which looks rather like a feather-duster hanging down in the water. The roots do a terrific job of filtering all sorts of nutrients, but they also do a great job of blocking spillways, skimmer inlets, etc.

Once the plants were dragged away from the spillway, the leaks ended.

Will we plant hyacinths again next year? You bet. The plants are beautiful and the goldfish and koi really love hiding beneath. But next year, there will be rules. They will have some boundaries to keep. We have a piece of old water-pipe stretched across the upper pond now, with the hyacinths behind, rather like a crowd behind a cordon along a parade route. We might invest in one of those floating circular “corrals” sold by water garden outfits exactly for plants whose enthusiasm needs to be curbed a bit.